I have a musical effects device (Leslie simulator). The effect speed can be toggled between fast and slow with a footswitch on the device, or and external footswitch plugged into a jack on the rear panel; I'd like to control the speed remotely, by MIDI control, using that external control jack. I have a MIDI controlled relay.
Unfortunately, due to a lack of foresight in the design, that relayspstwon't get the job down. A minor design modification would have allowed that without changing any of the current functionality, but that's beyond my control...
OK, this would be a cinch if I either modify the guts of the effects device (though ugly hack), or if I make a little external box with a battery. I don't want to do that. I'm looking for simple solutionon that fits inside the phone plug's shell, preferably. I don't see one, so I'm asking here, in case there's an obvious option I'm missing.
The first attachment shows how a dual footswitch can control effect speed (fast/slow) and "brake" (stopping the effect modulation). I don't care about the latterI just need to switch speed. As you can see, this requires a spdt switch, while my relay is spst. Internally, it's apparent (from measuring current) that the ring and tip of the phone jack go to two processor-readable inputs that are pulled up to +5V with 10K resistors; the sleeve is ground.
So, when the relay is closed, one of the inputs needs to get clamped to ground and the other needs to remain open (or otherwise high), and when open the inverse needs to happen.
The second attachment illustrates conceptually what needs to happen, but don't take it literallyit just seemed like an adequate way to explain what I'm looking for. (To start, that diode drop between base and emitter would pull the tip connection down even when the relay is open, so the two states would be 0,0 and 0,1; I need 1,0 and 0,1 for the tip,ring.)
I have a hunch I don't have the current nor flexibility to make this work without an external power source. Maybe there's a cmos device that will give enough isolation, but I suspect I still won't get the two states I need.
Any ideas? Like I said, it's a cinch with external power, so i don't need any help if the answer is to go with a little box and battery.
Thanks.
Unfortunately, due to a lack of foresight in the design, that relayspstwon't get the job down. A minor design modification would have allowed that without changing any of the current functionality, but that's beyond my control...
OK, this would be a cinch if I either modify the guts of the effects device (though ugly hack), or if I make a little external box with a battery. I don't want to do that. I'm looking for simple solutionon that fits inside the phone plug's shell, preferably. I don't see one, so I'm asking here, in case there's an obvious option I'm missing.
The first attachment shows how a dual footswitch can control effect speed (fast/slow) and "brake" (stopping the effect modulation). I don't care about the latterI just need to switch speed. As you can see, this requires a spdt switch, while my relay is spst. Internally, it's apparent (from measuring current) that the ring and tip of the phone jack go to two processor-readable inputs that are pulled up to +5V with 10K resistors; the sleeve is ground.
So, when the relay is closed, one of the inputs needs to get clamped to ground and the other needs to remain open (or otherwise high), and when open the inverse needs to happen.
The second attachment illustrates conceptually what needs to happen, but don't take it literallyit just seemed like an adequate way to explain what I'm looking for. (To start, that diode drop between base and emitter would pull the tip connection down even when the relay is open, so the two states would be 0,0 and 0,1; I need 1,0 and 0,1 for the tip,ring.)
I have a hunch I don't have the current nor flexibility to make this work without an external power source. Maybe there's a cmos device that will give enough isolation, but I suspect I still won't get the two states I need.
Any ideas? Like I said, it's a cinch with external power, so i don't need any help if the answer is to go with a little box and battery.
Thanks.
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